Curved nanographenes (NGs) are emerging as promising candidates for organic optoelectronics, supramolecular materials, and biological applications. Here we report a distinctive type of curved NGs bearing a [1,4]­diazocine core that is fused with four pentagonal rings. This is formed by Scholl-type cyclization of two adjacent carbazole moieties through an unusual diradical cation mechanism followed by C–H arylation. Owing to the strain in the unique 5–5–8–5–5-membered ring skeleton, the resulting NG adopts an interesting concave–convex cooperatively dynamic structure. By peripheral π-extension, a helicene moiety with fixed helical chirality can be further mounted to modulate the vibration of the concave–convex structure, through which the distant bay region of the curved NG inherits the chirality of the helicene moiety in a reversed fashion. The [1,4]­diazocine-embedded NGs show typical electron-rich characteristics and form charge transfer complexes with tunable emissions with a series of electron acceptors. The relatively protruding armchair edge also allows the fusion of three NGs into a C 2 symmetric triple diaza[7]­helicene which reveals a subtle balance of fixed and dynamic chirality.

Oxime ethers are of great importance in the fields of pharmaceutical chemicals and polymer materials. Herein, we developed a straightforward synthetic method of oxime ethers starting from tetrahydrofuran or other...

Correction for ‘Visible light-triggered synthesis of oxime ethers using tetrabromomethane as a mediator’ by Meng Tu et al., New J. Chem., 2022, 46, 23276–23281, https://doi.org/10.1039/D2NJ04615F.